Clamshell bucket



July 24, 1951 J. G. CAILLARD CLAMSHELL BUCKETS 5 Sheets-Sheet 1 Filed Dec. 15, l 947 l re-Mm? a M M July 24, 1951 Filed Dec. 15, 1947 J. G. CAILLARD CLAMSHELL BUCKETS 3 Sheets-Sheet 2 krm rae' J. G. CAILLARD CLAMSHELL BUCKETS July 24, 1951 5 Sheets-Sheet 5 Filed Dec. 15, 1947 Patented July 24, 1951 UNITED STATES PATENT OFFICE CLAMSHELL BUCKET Jean Georges Caillard, Le Havre, France Application December 15, 1947, Serial No. 791,725

In Francev March 24, 1947 My-invention relates to improvements in clam- .shell buckets.

Clamshell buckets, as used to carry loose goods, usually comprise two shells pivoted on a crosspart or strap and connected to the bucket head which :is'fixed to the cable carrying the'whole such as ores,. coal in large cobbles, etc., the bladeedges .ofztheshellshave a tendency to be forced upwards, sothat part of the materials lying betweenthe. said edges is left on the spot.

The object of this invention is to provide a .clamshell bucket which overcomes such dilficulties.

According to this invention, there is added to one of the parts to be brought together (that is the cross-partand th'e'bucket head) a rocking lever, one of the arms of which is connected by a tie-bar to the other part, while the second arm of said lever is fixed to the draw-rope or cable controllingthe closing movementof-the bucket. The ;,-1ever is so arranged that the armfixed to .the draw-rope is at a small angle, to this rope gor cable at the beginning of the closing move- .ment; and at a considerable angle at the end :of

such movement, while the arm fixed t the drawbar is at a considerable angle to the said drawbar at the beginning of the closing movement and is at a small angle to it at the end of said movement.

Due to such an arrangement, the linkage which brings the shells together has a low transmission ratio at the beginning of the closing movement While it has a high transmission ratio towards the end of said closing movement. It follows that the closing movement, while rapid at the beginning, ends slowly and applies a powerful force on the materials to be loaded.

In the annexed drawings:

Figs. 1, 2 and 3 are diagrammatic elevational views of a bucket comprising two shells hinged on a common axis and embodying the features of the present invention.

In Fig. 1 the bucket is shown in the open position.

Fig. 2 shows the bucket in an intermediate po- 1 Claim. (Cl.-37-,184)

2 sition during the movement which brings the two shells together.

Fig. 3 shows the bucket in the closed position.

Figs. 4 and 5 are diagrammatic elevational views of -.a bucket comprising shells pivoted around parallel axes and embodying the features of thepresent invention,,Fig. 4 showing the bucket in the open position and Fig., 5 showing it in the closed position.

Figs. 6 and 7 are elevational views of a clamshell bucket'of the same type as shown in Figs.,1 and 2, but in which the rocking lever is located on the axis of suspension of the head.

Fig. 6 shows the-bucket in the open position.

Fig. '7 shows the same bucket in its closed po sition.

The bucket shown in Figs. 1-3 comprises-two shells I and I hinged on a central axis 2.

The said shells are provided with ears l2, 12' on which bars or links 4 and'4 are hinged. These'links are also hinged on an axis 5 mounted in the bucket head, which is suspended from a rope. l3.

According to Figs. 1-3 a lever B is arranged on axis 2. The said lever is hinged at l on one end of a draw-bar 8,-the other end of which is hinged on axis 5 of the head.

Axis 5 is provided with an idle pulley I4 around which draw-rope or cable H) which controls the bringing of the two shells together is led. This rope or cable is attached to that end 9 .of lever-6 which is remote from hinge l.

The device operates in the following manner:

When the bucket is open, as shown in Fig. l, and it is desired to close it, a pull is applied to rope or cable Ill. Lever 6 is thus caused to revolve about hinge 1 while bearing on draw-bar 8, and axis 2 is lifted upwardly and both shells are thus rotated around the said axis.

At the beginning of the movement the direction of arm 2, 9 of lever B is not remote from the direction of the pull applied by rope I0, while arm 2, 1 is at a considerable angle to draw-bar 8. It follows that, for a small travel of rope or cable [0, axes 2 and 5 are appreciably brought together. The closing movement of the bucket is thus relatively swift during this first stage.

It may be seen by comparison of Figs. 1 and 2, that as the pull of rope I 0 is continued, the angle between arm 2-9 and rope l0 increases, and conversely the angle between arm 2-1 and drawbar 8 decreases.

During the final stage of the closing movement (from the position shown in Fig. 2 to that shown in Fig. 3) arm 2-9 of lever 6 is at considerable angle to the line of traction of cable 10, which thus acts with a large leverage. During the same stage, arm 2-1 is at a small angle to draw-bar 8. The closing movement is thus slackened, but the force tending to bring the shells together is greatly increased. A perfect filling of the bucket is thus obtained.

Figs. 4 and 5 show my invention as applied to a bucket comprising two shells l and I, hinged on a cross-part or strap 20, along two parallel axes 2i and 2| respectively and provided with toothed sectors 22 and 22', which mesh with one another. Shell l is hinged at 23 on a bar 24 the other end of which is in turn hinged on a lever 25 hinged at 23 on shell I. The said lever, the axis of suspension of which is shown at 26. is hung on rope 21 which supports the whole bucket.

According to my invention, a lever B is pivoted at 2 on strap 20. One arm of this. lever is inged at 1 on a draw-bar 8 at the other end of which is hinged on lever 25 in the vicinity of axis of suspension 25 The other arm of lever B is attached at 9 to draw-rope 10, which is led over an idle pulley 28. Both arms of lever B have the same direction with reference to drawbar 8 and draw-rope ID as already shown in Figs. 1-3 and the device gives the same advantages as that previously shown.

In the form of device according to Figs. 6 and '7, the rocking lever is located on the bucket head. One of its arms is connected, through a draw-rod, to the cross-part of the bucket, while its other arm is attached to the closing rope which is led around an idle pulley pivoted on the said cross-part.

These figures shown again at l and 1 both shells, hinged on axis 2 and provided with ears l2 and 12 which are connected by means of bars 4 and 4' to axis 5 on the bucket head hanging from rope 13.

In axis 5 of the head there is provided a lever B, one end of which is connected to one end of a draw-rod 8, the other end of draw-rod 8 being hinged to axis 2 about which the shells are arranged to turn.

Draw-rope I is led over an idle pulley 3|, pivoted on axis and thence on a counter-pulley 32 which runs idle on axis 2, and finally draw-rope II] is attached to lever 6 at its end 9 remote from end 1.

At the beginning of the movement, arm 5-9 of lever B has nearly the same direction as rope I0, attached at 9 and on the contrary, arm 5-1 is at a considerable angle to draw-bar 8. A small travel of rope Ill thus causes an appreciable drawing together of axes 2 and 5, so that the closing movement is relatively swift during its initial stage.

As the said movement is carried on, the angle between arm 5-9 and rope 10 increases, while the angle between arm 5-4 and draw-rod 8 decreases.

As the movement approaches its end, arm 5-9 is at a considerable angle to rope in fixed at 9, while the angle between arm 5! and tie-rod B is reduced. The closin of the shells thus ends slowly, but with a large force, which ensures a perfect filling of the bucket.

The arrangement and operation of the above described rocking lever are independent of the particular type of bucket used and the invention may consequently be used with buckets of quite dissimilar types.

Moreover it appears that my invention is not to be limited to the several devices illustrated by way of examples and that many modifications may be used within the scope of my invention as set forth in the appended claim.

I claim:

A clamshell bucket comprising two shells, axis means pivotally connecting said shells, a head, links pivotally connected at one end to said shells at a region spaced from the axis means. means connecting the other ends of said links to said head, a rockin bell crank lever pivotally mounted on said axis means intermediate its ends, a draw bar connected at one end to the head and at its other end with one end of the bell crank lever, and a draw rope carried by said head and connected to the other end of the bell crank lever, operable to close the shells of the bucket, the arm of the bell crank lever to which thedraw bar is connected lying at small angle with said draw bar when the shells are nearly closed, and the arm of the bell crank lever connected to the draw rope lying at an angle close to with the draw rope when the shells are nearly closed.

JEAN GEORGES CAILLARD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1 226,557 Seward Apr. 13, 1880 1,193,706 McWhirk Aug. 8, 1916 1,748,586 Robin Feb. 25, 1930 

